The suspect has been charged as an adult, and could face up to life in prison if convicted.

He used a handgun, shotgun, knife and machete in the attacks, police said.

According to CBS affiliate KREM, court documents released Tuesday show the 14-year-old called police following the killings and confessed.

The suspect told investigators that his father took medications and often beat him. He also claimed his father frequently talked about zombies and that he shot his father because he was afraid of his father "coming after him," court documents say, according to the station.

The documents say the suspect informed officers that he "hated" his brother and said he mentally prepared to kill his father and brother for about eight months prior to the attacks, according to the station.

The family had recently moved to Coeur d'Alene from California.

Samuel III is currently being held on $1 million bail at the Kootenai County Public Safety Building.